Improvement in hot-air engines



UNITED STATES PATENT OFFICE.

HENRY MESSER, OF ROXBURY, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR ENGINES.

Specilication forming part of Letters Patent No. 38,237, dated April 2l, 1863..

To all whom it may concern.-

Be it known that I, HENRY MEssEE, of Roxbury, in the county of Norfolk and State of Massachusetts, have invented an Improvement inHot-Air Engines; and I do hereby declare that the following, taken in connection with the drawings which accompany and form part of this specification, is a description of my invention sufticient to enable those skilled in the art to practice it.

Hot-air engines have heretofore been regulated to prevent excess of speed by so connecting the regulator with a valve that the regulator opens the valve and reduces the impelling-pressure by permitting more or less of the expanded air and gases to escape past said valve. When the speed. of the engine is reduced, the regulator again operates to close said valve, thus preventing further escape of the expanded air and gases. This arrangement, wllile it measurably answers its purpose, is defective, inasmuch as a portion of the generated caloric is lost, and inasmuch, also, as that it affords no means for bringing the engine to speed again, should it fall below in consequence of having to perform an increase of work, or for any other reason.

The object of my invention is to regulate hot-air engines without waste of the generated caloric, and in such a manner that the act of reducing excessive speed shall afford the meanspfor increasing diminished speed. This I accomplish as follows, referring to the accompanying drawings, in which- Figure 1 is a plan of so much of a hot-air engine as is necessary to illustrate the embodiment of my invention. Fig. 2 is a side elevation of thc same. Fig. 3 is a vertical section taken in the line z z, seen in Fig. 1. Fig. L.tis a section taken through the regulator (which is one of a well-known type) in the plane of the line :n :0, seen in Fig. 2.

a represents the base which supports th cylinder b, in which base is contained the furnace.

c is the main shaft, which is rotated in the manner usual in engines, from reciprocations of the main cylinder-piston.

The regulator is supported on a horizontal spindle by the stand d,f1xed on base a, and its balls e rotate in a vertical plane, so that the changes in the position .of the balls e, occasioned by variations in their number of revolutions, cause rectilinear movements of the piece f in the direction of the length of the spindle g. There are two cylinders secured to the base a, one, 7L, a mere reservoir, provided .with a closely-fitting piston, z', which is capable of moving vertically under the influence of a spring, j, or of a weight, and said cylin der is also intended to be provided with a safety-valve, (which is not shown,) so arranged as to relieve the lower end of the cylinder from excessive pressure. The piston-rod 7c is made hollow for the purpose of placing thereupon a spring safety-valve. The other cylinder, l, is a common force-pump, arranged with induction and eduction valves (as is usual with such pumps,and which, therefore, are not shown,) which operate when the piston m is reciprocated to force air at each stroke of the pump into the pipe t. The pipe t communicates between the reservoir and the force-pump, the communication being controlled by a valve, which, according to its position, lets the air be forced by the pump into the reservoir, or else lets it be discharged freely through the aperture 0.

Communicating between the lower part of the reservoir h and the furnace containing chamber a is a pipe, u, in which is a valve which permits or prevents communication between h a-nd a.

To suit the arrangement of the mechanism, the valves in t and u are of the rotary plug or cylindrical order, and are worked by rotation of the spindles n and p', these having upon their upper ends levers or rocker-arms n and p, the spindles being supported by a stand, q, fixed to a. In the ends of a p are pins which engage in grooves in f, so that it will be plain that reciprocations of f will cause partial rotation of the valves n and p. As a matter of detail in practical operation, the grooves inf are made a little wider than the diameter of the pins in n p, and springs are so applied to n p', or to wp, as to keep the pins in the center of said grooves when the regulator and the parts are in their normal position and the engine running at speed, which normal position is when valve n lets the air from the pump freely out of the aperture o, and when valve p closes communication between h and a..

The operation and effev ct of my invention are as follows: When the engine is running at proper speed, the force-pump discharges the air which is forced by it out of the aperture o but if the speed ofthe engine is increased, then the regulator-balls fly outward, the effect of which is to move the valves n and p. nis moved so as to close aperture o, and the motion of p does not open communication between h and a. Thus it will be seen that the pump now puts an additional loadl orresistance on the engine by causing it to labor in compressing air within 7L, which tends to reduce the speed of the engine to its normal rate where the aperture o is open and where communication is not established between h and a but if, now, on account of additional load put upon the engine,its speed is reduced below the normal rate, this causes a motion of f, which opens the aperture o and the communication between the reservoir h and a, y

thus supplying a with compressed air to urge the re and to be expanded by heat, and so increase the impellingpressnre as again to bring the engine up to speed.

It will now be plain that when the engine runs above speed a resistanceis brought upon it by the action of the regulator, which, while it tends to reduce the speed, also stores up a means for accelerating the speed when this falls below the normal rate, which means are applied by the action of the regulator whenever the speed falls below the normal rate.

By applying handles to the spindles u p', and by loosening the setscrews s s on n and p, the engine can be made, just before stopping, and irrespective of its rate of speed, to fill the reservoir h with compressed air, which, after stopping the engine, will start it again by simply admitting' this compressed air into a.

The matter of the details of the construction of the regulator, the pumps, and the valves forms no part of theinvention. Any of the well-known suitable forms of these may be employed, and the arrangement of parts may be modified io suit circumstances.

I claim- The described new method of regula-ting a hot-air engine by means arranged and oper ating substantially as herein set forth.

Executed this 16th day of February, A. D. 1863.

HENRY MESSER. I n presence of- J B. CROSBY, R. H. MArHrns. 

